Unimolecular Decomposition of Chemically Activatedsec‐Butyl andsec‐Butyl‐d1Radicals. The Reaction of H and D Atoms withtrans‐Butene‐2 and Butene‐1

摘要: H and D atoms were reacted with trans‐butene‐2 to produce vibrationally excited sec‐butyl sec‐butyl‐d1 radicals a range of excess energies respect C–C rupture. Previous work [R. E. Harrington, B. S. Rabinovitch, H. M. Frey, J. Chem. Phys. 33, 1271 (1960)] on butene‐1 has also been extended. Observed rate constants for the unimolecular decomposition these relative collisional stabilization obtained as function pressure. Possible competing side reactions are discussed evaluated. Butenyl radical formed by abstraction from butene‐2 tends retain geometric configuration original butene; also, ratio pentenes methyl coupling, illustrative two principal resonance structures, is (3‐methyl‐butene‐1) / (total pentene‐2)∼0.4. An expected energy isotope effect atoms, which give having ∼1.9 kcal/mole more vibrational than corresponding was seen. With or reactant, no evidence found H‐atom migration in formed. The disproportionation/recombination all systems be 0.63.